Process for waterproofing fibrous material.



No Drawing.

UNIT

sTArEs PATENT OFFICE.

PAUL r. BOVARD, or WIIIONA, MINNESOTA.

rnocnss ron WATERPROOFING nisnous MATEItIAL.

. I To all whom ztmay concern:

Be it known that I, PAUL F. BovARn, a citizen of the United States, residin at Winona, in the county of Winona and tate of Minnesota, have invented a new and useful Process for Waterproofing Fibrous Material, of which the following is a specification.

I by reason of decrease capillary attraction of the material so treated. b

The usual methods now practised are dependent upon the adhesion of oil bases to the surfaces of the fiber; the bonddepending upon the capillary attraction between the treated fiber and the oil, but water, espe cially if warm, breaks down this adhesion, because water appears to have a greater afiinity for the fibrous material than the oil.

My process onsists in subjecting the fibers as'hereinafter pointed out to the action of a solution of saponified oil and then fixing the fatt anhydrous salt of aluminum in the fiber cel s and upon the fiber surfaces.

To this end, I first provide a solution of saponified linseed oil or linseed oil soap,

neutral or slightly alkaline-too much alkalinity being detrimental in that it cuts the length of animal or vegetable fibers. I prefor to use a solution of linseed oil soap of from 1 Baum to 3 Baum at a temperature of about 150 Fahrenheit. It is beneficial to add casein to this soap solution as a size and hardener for the water repellent precipitates, the alkalinity of the soap being sufiicient to render the caesin soluble. One pound casein to 100 pounds of soap is sufii- Specification of Letters Patent.

Patented Oct. s, 1918.

Application filed June 4, 1317. Serial No. 172,679.

cient for satisfactory results. More casein may be used, but this is not essential.

In this solution I immerse the fibers in-a loose condition, the length of immersion depending upon the density of the fiber mass With 1 pound dry, loose fiber to 1 gallon of solution, about 30 minutes are required if the temperature is maintained at 150 Fahrenheit. The fibers should, of course, be entirely immersed during the period of the bath to insure investment.

After this treatment, the fiber is squeezed thoroughly to remove the excess of soap and size and then immersed in a solution of aluminum acetate of a strength of from 1 'Baum to 4 Baum, dependent upon the class of fiber being treated. Vegetable fibers in unfelted condition are thoroughly reacted upon with a 2 Baum' solution when treating 1 pound of dry fiber to each gallon of the solution for 15 minutes.

-I have specified the use of aluminum acetate, because I have found that this compound of aluminum is best fitted for my use, but it is also true that aluminum sulfate may be substituted therefor; though with coarse fibers, such as are used for insulating purposes, the result is less efiicient.

However, I regard the use of either of these compounds'of aluminum in my process as within the spirit of my invention.

The aluminum sulfate or aluminum acetate has a hardening effect upon the aluminum linoleate formed in the cells of the vegetable and animal fiber, and the presence of casein adds to the permanence of the investment.

The excess of aluminum acetate should be squeezed from the fiber.

' On thorough drying, the fibers will not take up water by capillary attraction. It is necessary that all moisture be expelled in drying for satisfactory results.

Having described my invention, what I claim as new and desire to protect by Letters Patent is: V

1. The method of treating fibrous material by immersing the same in a solution of saponified linseed. oil and casein, then removing the excessive moisture and again immersing the fibers in a solution of aluminum acetate, and finally drying the fibers.

2. The method of Waterproofing fibrous material which consists (1) in immersingthe same in a solution of saponified linseed oil and casein until the fibers are thoroughly saturated therewith, (2) in removing the teac es fibers from such solution and eliminating the free moisture by squeezing, (3) in im- 10 'mersing the fibers in a solution of an aluminum compound as specified, and finally in drying the fibers.

Whereof, I have hereunto subscribed my name to this specification.

PAUL F. BOVARD. 

